Add Private Space settings page

This involves:
1. Adding a new page for PS settings under Security & Privacy
2. Integrating the PS safety source with SafetyCenter.

Also, add the capability to create and delete PS from the page.
Creation is temporary to help with prototyping, and will be removed
finally.

Screenshots:
Private Space Entry point in Security & Privacy Settings:
https://screenshot.googleplex.com/4VHxNekjhxZHJwF

Private Space Settings page:
https://screenshot.googleplex.com/3Raw4wuymTHTgtM

Creating Private Space:
https://screenshot.googleplex.com/3dvzAH6V4kQmuYf

Private Space created:
https://screenshot.googleplex.com/Aj7nnF9uuUCa9Q5

Design doc:
https://docs.google.com/document/d/1CdjUjAE84-5ZEPRIfw5KYFjLVHtEZxc_sF0w95su8DA/edit?usp=sharing&resourcekey=0-dAACT9HRexY1IyoxMmkVlw

Bug: 286539356
Bug: 293569406
Test: manual
Test: atest DeletePrivateSpaceControllerTest
Test: atest UseOneLockControllerTest
Test: atest HidePrivateSpaceControllerTest
Change-Id: I9caf8e04e7fb2df36e60f607225e2931988ee692

src/com/android/settings/privatespace/PrivateSpaceMaintainer.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.privatespace;
+
+import static android.os.UserManager.USER_TYPE_PROFILE_PRIVATE;
+
+import android.app.ActivityManager;
+import android.app.IActivityManager;
+import android.content.Context;
+import android.content.pm.UserInfo;
+import android.os.RemoteException;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.util.ArraySet;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+
+import java.util.List;
+
+// TODO(b/293569406): Update the javadoc when we have the setup flow in place to create PS
+/** A class to help with the creation / deletion of Private Space */
+public class PrivateSpaceMaintainer {
+    private static final String TAG = "PrivateSpaceMaintainer";
+    @GuardedBy("this")
+    private static PrivateSpaceMaintainer sPrivateSpaceMaintainer;
+
+    private final Context mContext;
+    private final UserManager mUserManager;
+    @GuardedBy("this")
+    private UserHandle mUserHandle;
+
+    public enum ErrorDeletingPrivateSpace {
+            DELETE_PS_ERROR_NONE,
+            DELETE_PS_ERROR_NO_PRIVATE_SPACE,
+            DELETE_PS_ERROR_INTERNAL
+    }
+
+    /**
+     * Returns true if the private space was successfully created.
+     *
+     * <p> This method should be used by the Private Space Setup Flow ONLY.
+     */
+    final synchronized boolean createPrivateSpace() {
+        // Check if Private space already exists
+        if (doesPrivateSpaceExist()) {
+            return true;
+        }
+        // a name indicating that the profile was created from the PS Settings page
+        final String userName = "psSettingsUser";
+
+        if (mUserHandle == null) {
+            try {
+                mUserHandle = mUserManager.createProfile(
+                                userName, USER_TYPE_PROFILE_PRIVATE, new ArraySet<>());
+            } catch (Exception e) {
+                Log.e(TAG, "Error creating private space", e);
+                return false;
+            }
+
+            if (mUserHandle == null) {
+                Log.e(TAG, "Failed to create private space");
+                return false;
+            }
+
+            IActivityManager am = ActivityManager.getService();
+            try {
+                am.startProfile(mUserHandle.getIdentifier());
+            } catch (RemoteException e) {
+                Log.e(TAG, "Failed to start private profile");
+                return false;
+            }
+
+            Log.i(TAG, "Private space created with id: " + mUserHandle.getIdentifier());
+        }
+        return true;
+    }
+
+    /** Returns the {@link ErrorDeletingPrivateSpace} enum representing the result of operation.
+     *
+     * <p> This method should be used ONLY by the delete-PS controller in the PS Settings page.
+     */
+    public synchronized ErrorDeletingPrivateSpace deletePrivateSpace() {
+        if (!doesPrivateSpaceExist()) {
+            return ErrorDeletingPrivateSpace.DELETE_PS_ERROR_NO_PRIVATE_SPACE;
+        }
+
+        try {
+            Log.i(TAG, "Deleting Private space with id: " + mUserHandle.getIdentifier());
+            if (mUserManager.removeUser(mUserHandle)) {
+                Log.i(TAG, "Private space deleted");
+                mUserHandle = null;
+
+                return ErrorDeletingPrivateSpace.DELETE_PS_ERROR_NONE;
+            } else {
+                Log.e(TAG, "Failed to delete private space");
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "Error deleting private space", e);
+        }
+        return ErrorDeletingPrivateSpace.DELETE_PS_ERROR_INTERNAL;
+    }
+
+    /** Returns true if the Private space exists. */
+    public synchronized boolean doesPrivateSpaceExist() {
+        if (mUserHandle != null) {
+            return true;
+        }
+
+        List<UserInfo> users = mUserManager.getProfiles(0);
+        for (UserInfo user : users) {
+            if (user.isPrivateProfile()) {
+                mUserHandle = user.getUserHandle();
+                return true;
+            }
+        }
+        return false;
+    }
+
+    static synchronized PrivateSpaceMaintainer getInstance(Context context) {
+        if (sPrivateSpaceMaintainer == null) {
+            sPrivateSpaceMaintainer = new PrivateSpaceMaintainer(context);
+        }
+        return sPrivateSpaceMaintainer;
+    }
+
+    private PrivateSpaceMaintainer(Context context) {
+        mContext = context.getApplicationContext();
+        mUserManager = mContext.getSystemService(UserManager.class);
+    }
+}